This invention relates to computer systems and methods used in manufacturing resource planning, and, more particularly, to a computer system and method for determining the daily demand for raw materials and other manufacturing resources used in a manufacturing process. The calculation of daily demand by the computer system and method of the present invention is based on anticipated (forecasted) or actual orders for a manufactured product and certain predetermined parameters associated with the manufacturing resources. The results of the computer system and method, i.e., the planned-for demand of manufacturing resources, when used to schedule and allocate manufacturing resources, provides sufficient availability of manufacturing resources to meet unanticipated demand for a manufactured product.
In the manufacturing or factory setting, customer orders for various items need to be processed and produced in a certain amount of time (e.g., by a promised shipping date). For every product ordered which is not already in finished goods inventory and therefore available to fill the customer order, a product must be manufactured. To manufacture the product, certain manufacturing resources (such as raw materials, machine or production line time, shift worker hours, and the like) used in a predetermined sequence of events (the manufacturing process) are required. In order to efficiently utilize the manufacturing resources of the manufacturing plant or factory, and ultimately to fulfill a multiplicity of customer orders, the manufacturer generally employs a system and method for scheduling the use of different resources at different dates and times. The resource schedules allow the manufacturer to plan for having sufficient resources available.
In traditional batch manufacturing methods for producing goods, raw materials are ordered well in advance and kept in a stockroom as raw material inventory. Such manufacturing methods typically use a scheduled batch manufacturing technique in which products are scheduled to be created based upon a weekly or monthly planning schedule. Usually these products are produced as subassemblies or fabricated parts that are scheduled based upon the weekly or monthly requirements for finished products. These subassemblies are then assembled into the final product to fill actual customer orders, or to be placed into finished goods inventory.
Once an assembly or fabricated part is scheduled to be produced, a work order is generated, and the parts required to manufacture the assembly or fabricated part are obtained from the stockroom based upon a planned manufacturing start date and order quantity. Subassembly parts are often produced in the same manner as the final product. Thus, after being produced, the subassemblies are stored until they are needed for a final assembly. Because of the length of time of each process, a large inventory of subassembly parts and finished goods is often needed to satisfy an unanticipated or fluctuating customer demand. This scheduled manufacturing process therefore requires a large amount of space for holding raw material inventory, subassembly parts inventory and finished goods inventory. Additionally, storing such large amounts of inventory results in additional costs related to loss and damage to raw materials, subassemblies and finished goods over time.
Computer software programs have been developed to efficiently accomplish many of the calculations used in batch manufacturing systems by materials planners in a manufacturing company to schedule and track raw materials inventory, batch subassemblies and fabricated parts. Typically, such computer software programs can calculate and determine, and even generate purchase orders, for obtaining the anticipated amount of raw materials required based on the planning schedule input by the materials planners. These computer software programs can also assist in the scheduling of manufacturing resources other than raw materials, such as the scheduling of manufacturing production lines and shift worker crews.
Other scheduling methods have been developed to assist in the planning of the acquisition of raw materials required in the manufacturing processes that utilize manufacturing methodologies other than batch manufacturing methods. Computer scheduling systems that employ these scheduling methods are generally referred to as materials requirement planning (MRP) systems. Typically, MRP scheduling systems assume an infinite capacity of machinery, shift worker hours, and the like, and the MRP system determines the amounts and types of raw materials that must be on hand at particular dates/times for a given manufacturing plant with given forecasted or actual orders.
Manufacturing resource planning (MRP II) systems, an improvement over the typical MRP systems, may also be used to schedule and allocate all kinds of manufacturing resources. MRP II systems generally also use customer orders and marketing forecasts to determine the quantity of manufacturing resources needed at any given time to produce anticipated customer orders. In MRP II systems, the number of days that it takes to manufacture a product from the time the initial manufactured components or subassemblies are produced until the final product is shipped is called the manufacturing lead time or pipeline. A long lead-time, caused by the subassembly manufacturing process, may make it difficult to react quickly to unanticipated customer orders. The lengthy process of long manufacturing lead times, queues for each subassembly, and frequent trips to the stockroom to obtain materials will introduce long periods of delay between manufacturing steps, and thus, a long period of time between the customer""s order and the completion and shipment of that order.
One of the more significant problems of these MRP II systems is that the production schedule is created well in advance, and cannot be altered easily. In addition, the computer software programs used in these processes generally lack the ability to easily adjust schedules when conditions change. If the manufacturing process is to become more flexible, the computer software programs used for scheduling should also become more flexible. In the typical MRP II system, however, the production quantity, or total demand on resources, is manually set by a master scheduler, and cannot easily be adjusted.
Therefore, prospective scheduling systems have been developed which identify where and when resource magnitude or timing constraints will be violated if a certain number of orders are received so that these violations may be resolved before they actually happen. However, relationships and constraints associated with products and processes must be accurately modeled in these systems if they are to predict future events with any degree of precision. Models can include process yield and probability factors, but cannot predict random events such as equipment failure, missing parts, or bad weather. Yet, random events must be considered and planned for in advance so that excess material and capacity stores can be used to prevent bottlenecks. The use of alternative resources can also prevent bottlenecks. In either case, timely recognition and response (i.e., scheduling around) is essential to maintaining productivity.
In any manufacturing environment, timely and precise resource plans and schedules are often a critical success factor. Material requirements planning systems enhanced with the above considerations can be used to determine future material requirements and potential shortages due to changing conditions and unexpected events, including unanticipated customer orders. The result of a successfully implemented system would be to reduce inventory and minimize material disruptions. However, even these kinds of material requirements planning systems function well only with definite and planned requirements (i.e., manufacturing systems in which products are built to meet forecasted amounts rather than actual customer orders), and where design changes (and therefore, changes in the manufacturing process and/or type and amount of raw materials) are infrequent.
Additionally, increased manufacturing flexibility, particularly in a factory that produces more than one product, creates a need for long term resource planning strategies based on production capacity and anticipated product mix. Similar scheduling methods may be applied to control other business operations including production capacity, distribution, equipment maintenance, and shop floor scheduling. Frequent adjustments to schedules may be required because small changes in requirements, status, products, processes or their constraints may result in dramatic changes to the requirements for many different resources.
It is thus apparent that there is a need for an improved system and method for automatically calculating the prospective total daily demand for manufacturing resources and automatically adjusting the demand, based on parameters relating to the resource, to accommodate unanticipated customer orders or other changes to the manufacturing process (including changes in the availability of raw materials). There is a further need for such a system that can allocate and schedule manufacturing resources to produce the maximum number of customer orders while minimizing the overhead and costs associated with maintaining excess resource inventory for capacity. The present invention meets these and other needs.
Generally speaking, in accordance with the present invention, an improved method and system to prospectively determine the daily demand for manufacturing resources in a manufacturing system is provided. More specifically, the method and system of the invention provides a projection of demand on manufacturing resources over time based on one or several of actual customer orders, future forecasts of customer orders, historical data of past customer shipments, current amounts of finished goods inventory, and predefined parameters related to the manufacturing resources.
The method and system is able to calculate when certain amounts of raw materials or other manufacturing resources are going to be needed based on when a customer order needs to be filled, and hence the system and method can additionally determine the date when the manufacturer needs to purchase or produce raw materials, refills, and the like (based on known supplier or manufacturing lead time), and plan to make those other resources available to produce the goods in time to meet a promised shipping date for an order to the customer. The invention therefore manages materials and other resources and may integrate the planning of manufacturing resources with an order acknowledgement system.
Furthermore, the method and system can allocate and schedule manufacturing resources, such as machine time or production line utilization, in a manner which minimizes waiting time of items to be fabricated, increases the productive use of the machine (i.e., decreases waste or leftover machine time) and maximizes the flexibility of the machine to support demand for several different products. For example, in a firing step of the factory process, it is ideal to place a maximum amount of items in a kiln each time the kiln is used. The system and method of the invention allows the kiln resource to be used (consumed) by more than one product at a time. The invention therefore provides efficient manufacturing resource plans that support customer demand requests over many products.
The system includes a database for storing predefined parameters, information about customer orders, and historical data. An input device is provided which allows an operator of the system to enter the parameters or other information. Alternatively, the input device may be linked to the output from various controlling mechanisms in the manufacturing process. An output device is provided to generate reports detailing the planned allocation of resources. In the case where raw materials are allocated for scheduled production, the output device may generate purchase orders. Alternatively, the output device may be linked to the input from various controlling mechanisms in the manufacturing process, or even linked to an ordering system of suppliers or customers.
The above and other aspects of the invention are accomplished in an improved method and system that determines the total demand for a manufacturing resource for each day over several time periods specified by the user of the system. For example, within the first time period, from the current date (i.e., today) up to a demand time fence (i.e., the manufacturing lead-time), the total demand may be altered, even though a quantity of products is already in production. The system of the invention utilizes minimum and maximum finished goods inventory targets to either supply additional products or consume excess products being made. Additionally, products with a delayed specific identity, i.e., generic finished goods orders, can be interchanged among related products within a generic finished goods order family prior to the step in which the product becomes unique.
For several periods beyond the demand time fence, called flex fence periods, the total demand for each day can vary by a percentage amount or a fixed number up and a percentage amount or a fixed number down (which percentage or number may be the same or may be different) determined by the user for each product. Each period can have a different percentage, for example, and each period can have a different number of days, however all days within a period use the same flex percentage for the period. The percentage amounts or fixed numbers represent planned-for excess capacity for which resources are made available in order to meet customer orders for the product that exceed forecasted amounts. The flex fences create available resource capacity that moves in the direction of solid customer order trends, and is determined by a number that includes weighted factors for one or more of current production amounts, future order forecasts and past customer shipment history.
Once the quantities within the flex periods have been determined, the system produces a plan for ordering raw materials and scheduling other manufacturing resources sufficient to build the total anticipated demand plus the flex fence demand. Thus the system creates the flexibility to fill customer orders up to the amounts determined by the upper flex fences.
If an order is received for a date beyond the demand time fence, and the order is larger than the total anticipated demand and the additional flex demand (called the high flex amount) for that date, the system and method can recalculate total demand for all days beyond the demand time fence date and prior to the order date to attempt to produce the total demand quantity necessary to fulfill the order in a process known as smoothing. In calculating the demand for manufacturing resources up to the flex fence amounts, the system uses an algorithm that adjusts the quantities in a manner that prevents the total demand quantity for any day from exceeding the amount of raw material and other resources that was planned to be available for that day. Therefore, unanticipated customer orders outside of the high flex amounts on the order date can be met, even though the manufacturer has only the flex amount of excess resource capacity and materials, by smoothing the demand over prior days.
The improved system and method of the invention also provides for intermediate reporting of the status of customer and finished goods replenishment orders at various points during the production pipeline. If a problem occurs, it is immediately recognized and reported so that the system can take an action to attempt to resolve the problem, such as by consuming demand for resources from other stores, e.g., from non-committed customer orders or marketing orders, available-to-promise amounts, finished goods inventory or finished goods replenishment orders.
The method and system of the invention may also solve a wide variety of resource management problems. Resources which may be managed include raw materials, machine or production line time, shift worker hours, other labor, space, power, or any other quantity whose constraint affects the ability to accept orders for the delivery of goods or services.
For example, in construction work, the scheduled use of resources may include construction workers with general or specialized skills, various single task or multi-purpose equipment, and materials requirements; in transportation, the efficient use of special or general purpose vehicles to transport people, materials, and equipment between a multitude of locations; in health care, the scheduled use of beds, operating rooms, general or specialized staff, and fixed or mobile equipment. Other uses of the system and method of the invention will readily be apparent to those who understand the embodiments disclosed herein.
Accordingly, it is an object of this invention to provide a system and method for planning, scheduling and allocating manufacturing resources in order to maximize manufacturing flexibility to meet unanticipated customer orders while minimizing the inventory costs and other costs associated with maintaining excess capacity of such resources.
Another object of the invention is to provide a system and method which may generate order acknowledgement projections based on whether sufficient manufacturing resources may be allocated in time to produce a customer order by a customer requested build completion date.
A further object is to provide a system and method which calculates when manufacturing resources are going to be needed and, hence, in what amount a manufacturer should buy raw materials, plan machinery time and schedule shift workers to operate the manufacturing line.
Yet another object is to provide a system and method which takes into account the capacity of each machine and staffing pool of the plant. To that end, each manufacturing resource is assigned a manageable amount of work and is not overloaded with assignments. In a like manner, reasonable amounts of the inventory of raw materials and subassemblies are calculated and maintained on hand in order to provide sufficient capacity to meet unanticipated demand, while minimizing the carrying costs and risk of damage or loss of such inventory.
Yet a further object of the invention is to provide a system and method that provides management of a company with detailed resource analysis information and plans.
Still yet another object of the invention is to provide a system and method that may modify order acknowledgement and resource planning projections each time new information is input.
Still other objects and advantages of the invention will in part be obvious and will in part be apparent from the following detailed specification.
The invention accordingly comprises the several steps and the relation of one or more such steps with respect to each of the others, and the system embodying features of construction, combinations of elements and arrangement of parts which are adapted to effect such steps, all as exemplified in the following detailed disclosure, and the scope of the invention will be indicated in the claims.